The invention herein relates to a bearing construction for rollers used in supporting and guiding the metal strand formed in a continuous casting process. The process itself and the apparatus used therewith is generally described in the patent to Jackson, U.S. Pat. No. 4,023,612 issued May 17, 1977.
In general, the continuous casting process involves the gravity pouring of molten metal, such as steel, into the upper end of a box-like mold which has an open bottom. The mold is cooled, such as by water flowing through its walls.
As the metal cools, it forms a strand or slab having an outer, solidified skin that forms where the molten metal contacts the interior, cooled walls of the mold, and an inner molten core. This strand emerges downwardly through the open lower end of the mold. Then the strand is curved into a horizontal direction. The elongated strand is guided and supported between roller aprons which comprise a large number of support rollers. Meanwhile, water sprays are directed, between the rollers, upon the outer surface of the strand to continue the cooling process so that the strand ultimately becomes completely solidified.
As the slab or strand moves in the horizontal direction, supported upon rollers, it is cut into lengths. The cut slab lengths are then removed for further processing, such as for rolling into sheet steel or the like.
The strand or slab is typically rectangular in cross section, as for example four to nine inches in thickness and about three to five feet in width. The support and guide rollers engage the wide opposite faces of the strand. Because of the intense heat, substantial loads due to the weight of the metal and the tendency of the strand to bow outwardly under the internal ferrostatic pressure of the molten core, and the water and steam atmosphere surrounding them, the bearing constructions and supports for the rollers tend to wear out or fail relatively quickly. When this happens, this requires shut-downs of the operation, replacement of damaged or disabled parts and then start-ups which are time consuming and difficult because of the continuous nature of the casting operation.
The rollers are formed of an internal, non-rotatable shaft whose opposite ends are secured to end rails. Each shaft may be additionally secured between its ends to intermediate rails. Tubular roller sleeve sections are rotatably mounted upon each shaft. These roller sleeve sections engage the adjacent metal strand face. Thus, bearings are arranged between the rotatable sleeve sections and their shafts upon which they are mounted for rotation.
The invention herein relates to an improved bearing construction for the rollers, which construction substantially increases the life of the bearings, as compared to prior bearing constructions.